Telephone system



A L-RAY. TELEPHONE SYSTEM. APPLICATION FILED JAN. 26. 1915. RENEWED AUG. 26.1918.

Patented May 20, 1919.

vmczmu, 7

d e M5 5 A. 1. RAY.

TELEPHONE SYSTEM. APPLICATION FILED JAN. 26, 1915- RENEWED AUG; 26. 1918.

1,304,869; I Patented May 20, 1919.

2 SHEET'S-SHEET 2.

R IIIIIIIIIIIHII" UNITED STATES PATENT OFFICE.

ARTHUR J. BAY, OF LIVERPOOL, ENGLAND, ASSIGNOR TO AUTOMATIC ELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

TELEPHONE SYSTEM.

Application filed January 26, 1915, Serial No. 4,573. Renewed August 26, 1918. Serial No, 251,541.

T 0 all Whom it may concern.

Be it known that I, ARTHUR'J. RAY, a citizen of the United States, residing at Liverpool, county of Lancashire, England, have invented a new and useful Improvement in Telephone Systems, of which the following is a specification.

This invention relates to modifications of circuit arrangements for operating subscrib ers meters or call registers in telephone systems. The invention is particularly, though not exclusively, applicable to automatic telephone systems in which the subscribers lines are connected with the first group selectors through the medium of preliminary switching devices, either call finders or trunk selectors. The invention is further applicable to automatic systems in which the direction of current in the calling line is reversed on the response of the called subscriber, and is therefore in the nature of an improvement of the called subscribersand close the cir-' cuits of the calling'subscribers meters which are connected-m r to' the contact springs of the 'relaysthrou'gh extra bank contacts of the Preliminary switches, when'the switches are operated.

In Figs-:1 and 2 of the accompanying.

drawings there is shown a complete connection from a calling telephone A to it called telephone A in an automatic telephone systemin connection with which it has been chosen to illustrate the invention; On these drawings, the calling lines obtainconnection with the first numerical switch through two series of non-numerical switches C and C This arrangement is similar to that shown in British Patent No. 1421 of 19-10. The

trunk lines to which the switches C have Specification of Letters Patent. Patented May 20,,1919. 7

access are shown leading direct to connector The substation A (Fig. 1) may be of any suitable or approved type, and, as shown 1 herein, comprises the usual receiver 2, transso-called automatic substation, it is also provided with an impulse transmitter or calling device, which is herein represented by a pair 'Initter 3, ringer 4: and condenser 5. Being a of impulse springs 6 and 7 and an impulse.

wheel 8, which latter may be controlled by a finger hold dial orv other device to separate the springs 6 and 7 momentarily anumber of times for each digit of the numher to be called. v

The subscribers individual switch C. is of the general type of subscribers switch shown in British Patent No. 26301 of 1906, more closely resembling, however, the particular type shown in British Patent No. 14:21 of 1910. This line switch comprises, among other details, a plunger (not shown) attached to the end of a so-called plunger arm 9, which is controlled by a magnet 10, which comprises an operating winding 11 and a holding winding 12. This magnet also controls the cut-off armature 13. The winding 11 operates botl1 plunger arm 9 and armature 13, while winding 12 is stron enough only to operate the armature 13 an to hold the plunger arm 9 in its operated position. i

When the plunger arm is attracted, the line connection is extended through a set of springs 14, 15, 16, 17, 18, 19, 20 and 21 to a secondary switch C A so-called master switch D maintains theplungers of idle switches in position to engage an idle trunk line in a Well-known'manner.

Each subscribers line is provided with a call reglster M, the magnet 22 of which is 'structed and adjusted that it requires both its windings to be energized in the same direction to attract its armature. The relay 23 has a sufiiciently high resistance to prevent the meter magnet 22 energizing in series with it.

The secondaryswitch C is, in general, similar to the primary switch C. The detail differences between these switches will be evident from the description of the operation which is to follow. A group of switches C is controlled by a common masterlswitch D which is similar to the master switch D,

Since the operation of the invention de-.

scribed herein is not dependent on the operation of the master switches, it is not thought necessary to describe their construction and operation herein. These switches are fully described in the publications hereinabove referred to.

The connector switch E is of the same general type of connector switch as disclosed in United States Letters Patent No. 815176, granted March13th, 1906, to Keith, Erickson and Erickson, the circuits, however, being modified in a manner similar to that shown in British Patent No. 1421 of 1910 to adapt the switch to operate in-a system in which the central office apparatus is controlled by impulses delivered over the two sides of the line in series. The connector is provided with a shaft (not shown) carrymg the wipers 25, 26 and 27, which is controlled by the vertical magnet 28 and the rotary magnet 29. The usual side switch comprising the wipers 30, 31, 32 and 33 is controlled by the private magnet 34 in the usual well-known manner. The magnet 49 is the usual release magnet. The line relay 35 is connected with the calling line through the reversing springs of the socalled back bridge relay 36. The ringing relay 37 is the means through which ringing current is applied to the called line.

The called substation A together with its individual switch C and meter M are simi lar in all respects tothc substation A, together with its individual switch C and meter M.

A general description of the apparatus having been given, it will now be explained how the connection, is extended. from the telephone A to the called telephone A and how the completed call is recorded on the cal-ling subscribers call register M. It will be assumed that the number of the called line is number 20.

Upon the removal of the receiver from the switch hook at the telephone A, preparatory to making a call the circuitof the line relay 40 is closed from. the battery lead 50 through relay 40, springs 41 and 42, thence over the line to and through the telephone A and back over the other side of the line and through the springs 43 and 44 to earth G The relay '40, upon energizing, closes the circuit ot the operating wind ng 1.1 winch onthe springs 57 and 58,

whereby the line circuit is extended through the springs 14 and 15 and 16 and 17 to an idle secondary switch G On the closing of springs 20 and 21 of switch C a circuit is closed from battery lead 50 through relay 23 of the selected junction line, springs 21 and 20, and meter magnet 22 to earth G The current in this circuit is not sufficient to operate the meter magnet 22, but the relay 23 is operated, earthing the master switch bank contact 45 to mark the junction as engaged. The relay 23 also closes a circuit from earth G through springs 46, operating winding 47 of switch C springs 51 and 52, relay 54 and contacts 55 and 56 to battery lead 50. The winding 47 attracts the plunger arm of the switch to extend the line connection through 59 and 60, and con- 'ductors 61 and 62 to the connector E, and to shift the connection of winding 47 to battery through the high resistance holding winding 63 instead. of through relay 54 and contacts and 56. The slow-acting relay 54- is energized only for a short time to provide a holding circuit from. earth G for the winding 12 of the switch 0 till said circuit is earthed at the connector E which is brought about as follows:lVhen connec tion is extended to the connector 16 over the conductors 61 and 62, a circuit is closed extending from earth through the lower winding of the c nncc'tor line relay 35, a normally closed contact of relay 36, conductor 62, springs and 59, 17 and 16, telephone A, springs 14 and 15, left hand winding of relay 24, springs 57 and 58, conductor 61, a contact of relay 36' and upper winding of relay 35 to battery lead 50. Rela 35, upon energizing, closes the circuit of relay 64 which in turn closes a circuit from earth Gr through the springs 65, conductor 66, relay 67, springs 68 and 69, conductor 70, springs 19 and 18 and holding winding 12 of switch C to battery lead 50. From the spring 18, a connection extends to the connector private bank contacts of the calling line over which said contacts are earthed to mark the line as engaged. From the conductor 70 in the circuit traced above a branch circuit extends through theright hand winding of relay 24 to battery lead 50. The current in this winding is opposed at this time by the line current in the other Winding and the relay is not operativcly energized. When all the junction lines outgoing from a group or board of secondary switches are in use simultaneously, the relays 67'of all these junction lines cotiperate to close the circuit of relay 98 which opens the contact 71 to prevent the master switch D operating continuously. During the time the outgoing j unctions are all engaged, all the incoming junctions are guarded against seizure by the deenergization of relay 72.

The calling subscriber now operates his calling device for the first digit 2 of the called number, whereby the substation impulse springs 6 and 7 are separated twice momentarily, each time breaking the circuit iground G of the connector line relay The relay 64 of the connector switch being slow acting does not deenergize during the momentary interruptions of its circuit by the line relay 35, and consequently, each time the latter relay denergizes, an impulse is transmitted over the circuit extending from ground G, through the contact of springs 76 and 75, springs 77 and -7 8 of the relay 6%, slow acting relay '79, the vertical magnet 28 and the side switch wiper 30 in first position to battery B. The vertical magnet receives two impulses over this circuit and operates to raise the switch shaft and wipers to a position opposite the second level of bank contacts. The relay 79, which was included in series with the vertical magnet, remains in its energized position during the entire time that impulses are being transmitted through it and operates to'close the circuit of the private magnet 34. from ground G, through the contact of springs 80 and 81 and the said magnet to battery B. After the last impulse is delivered, the relay 79 opens the circuit of the private magnet 34, which, upon deenergizing, permits the side switch to advance from first to second position in a well-known manner. The movement of the side switch wiper 30 from first to second position transfers the battery connection from the vertical magnet 28 to the rotary magnet 29. The calling subscriber now operates his calling device for the last digit 0, in response to'which the connector line relay operates to transmit ten impulses through the rotary magnet 29 in series with the relay 79, whereby the shaft and wipers are rotated on to the contacts of the desired line. The circuit extends from through the contact of springs 76 and 75, springs 77 and 78, relay 79, springs 82, the rotary magnet 29 andthe side switch wiper 30 in second position to the battery B; If the called line is idle, the private magnet 34 denergizes when its circuit is broken by the relay 7 9 after the last impulse is delivered to the rotary magnet 29. The denergization of the private magnet 34 allows the side switch to advance one more position, that is, from second to third positime -By the engagement of the side switch wipers 32 and 33 with their third position contact-points the connection is completed with the called substation. The circuit for the bridge cut-ofi' winding of line switch C? extends from ground G through the side This circuit extendsswitch wiper 31 in third position, private wiper 26, conductor 8% and the said cut-01f winding to the battery lead 100. The said \vim mg; upon energizlng, operates to (115 connect the line w1nding85 of the line switchv connector switch. By theengagement of'the, side switch wiper 30 with its third position contact point, the circuit of the ringing relay 37 is closed. The circuit extends from ground G9, through the interru ter 86, relay 37, springs 87 and the side switch wiper 30 in third position to the battery B. The

ringing relay, upon energizing, disconnects the called line fromthe calling and bridges the ringing generator R across the called line. The ringing relay is energized only intermittently through the medium of the interrupter 86. Upon the response of the called subscriber, his line is provided with talking current through the back bridge re;

lay 36. 'The relay 36, upon energizing,

closes the circuit of the ringer cut-ofi' relay 88. This circuit extends from ground G3 position, contact of.springs 89 and the relay 88 to battery B. The relay 88, upon through the side switch Wiper 31 in third 2;

ener izin interru ts the (IllClllt Of the ringer relay 37 at the springs 87 and closes] I a locking circuit for itself through the springs 90 independent of the springs 89.

A further result of the energization of the back bridge relay ;36,'upon response of the called subscriber, is the transposition of the connection of the windings of the line relay 35 with regard to the line, whereby the direction of the current in the calling line is reversed, and consequently in the left hand windin of the meter controlling relay' 24 (Fig. 1 This reversal of current in one of;

the'windings of the relay 24 causes the two windings to assist each other, and the relay,

is operatively energized. At the contact of springs 91, the relay 24 shunts therelay 23' by the low resistance 93 thereby increasing the current in the meter magnet 22 sufliciently to cause it to operate to register the call. The contact. of the springs EH provides an earth connection for holding the C in case the relay 23 is dei ncrgized when shunted by the reslstancc 93. ()n energizing,

the relay 24'short circuits. its left hand winding at the contact of springs 95 and the switch relay is thereaftermaintained energized bv its right hand winding'alone. After the conversation is completed, the connection is released by the hanging 1i p of the receiver at the calling telephone, thereby the circuit of the connector line relay 35 is opened. This f opens the circuitof the relay 64 which deenergizes and closes the circuit of the release magnet {19.

This circuit extends from earth Gr through springs 76 and 7 5, 77 and 96 shaft controlled contact 97 and magnet 49 to battery B. The switch is restored to normal 'position immediately on the energiza- 5 tion of the magnet 49. The relay (ll, on deenergizing also opens the holding circuit of the switch C and meter relay 2%. The holding circuit of the switch C is opened by the deiinergization of relay 2* and said switch is permitted to restore. to normal position.

In casethe wanted line is already engaged, the connector does not complete connection therewith, the calling subscriber being given a busy signal in a well known manner, and

15 since the relay 36 is not energized, the calling subscribers meter is not operated.

lVhile a particular form of the invention has been shown herein, and the invention has been illustrated in connection with a particular type of telephone system, it is evident that it may be applicable in other forms and in other types of systems.

It is further evident that 'the relay is not necessary it' the secondary line switches are controlled over the line circuit in the same manner as the primary switches are controlled, or in systems where secondary switches are not employed. In such cases the master switch contacts may be connected lines in known manner.

Having thus described my invention, what I claim and desire to-sccure by Letters Iatent, is:

1. In a telephone system, a motor, a plurality of differential relays, and a circuit for said' meter controlled by any one of said relays.

2. In a telephone system, a meter, a progressively movable switch associated with said meter, a plurality of diii'crential relays, a circuit for .tICll relay, a busy test circuit associated ;'with each relay, said progressively movable switch controlled over said test circuits to find one of saiddiffcrcntial relay circuits to control said differential relay and to in turn control the operation of said meter.

3. In a telephone system. a calling line, 0 a meter associated therewith, trunk lines, means for comiccting said calling line with one of said trunk lines, and a dilierential relay in said trunk line for controlling the operation of said meter.

4. In a telephone system, calling lines, a meter associated with each of said lines, a differential relay common to said lines, means for connecting any one of said lines with said differential relay, said meters controlled by said differential relay.

5. In a telephone system, a calling line, a meter associated therewith, trunk lines, a differential relay and a controlling relay for each of said trunk lines, a busy test circuit to the holding conductor of the junction for each trunk line and means controlled over said busy test circuit for extending a, connection from said calling line to one of said trunk lines and for closing a circuit through said meter and said controlling relay, without operating said meter, and means for energizing said difierential relay to shunt said controlling relay to thereby operate said meter.

6. In a telephone system, a calling line, a measured service device associated therewith, trunk lines, means for connecting said calling line with one of said trunk lines, and a differential relay in said trunk line for controlling the operation of said measured service means.

7. In a telephone system, a calling line, a.

meter associated therewith. trunk lines, a progressively movable switch for connecting said calling line with one of said trunk lines, and a differential relay in said trunk line for controlling the operation of said meter.

8. In a telephone system, a calling line, a meter associated therewith, trunk lines, means for connecting said calling line with one of said trunk lines, a differential relay in said trunk line, and means controlled by said differential relay for controlling the operation of said meter.

9. In a telephone system, a calling line, a meter associz'ited therewith, trunk lines, means for connecting said calling line with one of said trunk lincsfa differential relay in said trunk line for controlling the operation of said meter, means associated with said trunk line for extending a connection to a progressively movable switch, and means in said switch for controlling said difl'erential relay to in turn control the operation of said meter.

10. In a telephone system, a calling line, a meter associated therewith, trunk lines, means for connecting said calling line with one of said trunk lines, a differential relay in said trunk line for controlling the operation of said meter, means associated with said trunk line for extending a connection to a called telephone line, said differential relay controlled from said called line for current How in the calling line, means con-' trolled from said called line for reversing said current flow to the calling line. said dificrential relay operating in response to said reversal of current to operate said meter.

12. In a telephone system, a meter, a progressively movable switch associated with sald meter, a plurality of differential relays,

a circuit for each relay, a busy test circuitv associated with each relay, said progres sively movable switch controlled over said test circuits to find one of said differential switch controlled over said test circuits to find one ofsaid relay circuits to control said relay and to in turn control the operation of said meter, means associated'with said relay for extending a connection to another progressively movable switch, and means in said other switch for controlling the operation of said relay.

14. In a telephone system, a calling line, a meter associated therewith, trunk lines, means for connecting said calling line with one of said trunk linesya difierential relay in said trunk line for controlling the opera-- tion of said meter, means in-said trunk line for extending a connection to another progressively movable switch, means in said other switch for establishing a current flow in one direction in said relay without operating the same, and means for reversing said current flow to operate saidrelay to in turn control said meter.

15. In a telephone system, a calling line,

- a meter associated therewith, trunk lines,

means for connecting said calling line'with one of said trunk lines, a difl erential relay in said trunk line for controlling the operation of'said meter, means for extending a connection from sald trunk to a progressively movable swltch and means 1n' said switch for varying the current in said trunk line to operate said difierential relay to in turn control said meter.

16. In a telephone system, a calling line,

a meter associated therewith, trunk lines,

means for connecting said calling line with one of said trunk lines, a differential relay in said trunk line for controlhng theoperation of said meter, means for extend ng a connection from said trunk. to a progressively movable switch and a relay in said switch for varying the current in said trunk line to operate said differential relay to in turn control said meter.

17 In a telephone system, a calling km,

a meter associated therewith, trunk lines,

tion of said meter, means forextending a connection from said trunk to a progressively movable .switch and a relay in said switch controlled by a called subscriber to vary the current in said trunk line to operate said difierential relay to in turn control said meter.

18. In a telephone system, a calling line, a meter associated therewith, trunk lines, means for connecting said calling line with one of saidtrunk lines, a differential relay in said trunk line for controlling the operation of said meter, means associated with said trunk line for extending a connection to a called line and to thereby establish a current flow in the calling line, means controlled from said called line for varying said current How to the calling line, said diflerential relays operating in response to-said variation of current to operate said meter.

19. Ina telephone system, a calling line, a meter individual to said line, a plurality of trunk lines, a. differential relay and a test circuit for each trunk, means controlled over said test circuit for extending a connection from said calling line to oneof said trunk.

lines, means associated with said trunk line for extending the connection to a called line, i

said differential relay controlled from said said meter.

20. In a telephone system, subscribers lines each provided with a meter or call register, trunk lines less in number than the number of lines for use in connecting calling and called lines, means controlled over connected called lines for altering the current flow in connected calling'lines, and'relays for controlling the meters of connected can;

ing lines in response to alterations of current flow therein, each relay being individual to a trunk line whereby a small number of relays is enabled to control a large called line to in'turn control the operation of the circuit of a connected calling line, and a .meter control circuit completed during the establishment of a connection whereby the meter associated with the calling line is brought under control of said relay.

22..In a telephone system, subscribers lines,each provided with a meter or call register, means including a trunk line for called line, a relay individual to said trunk line-for controlling the meter associated'with connecting any linev when calling with a A a connected calling line, and a winding of said relay including a talking conductor of the trunk, whereby the relay is rendered responsive to a current variation in the calling line circuit. 7

In a telephone system, subscribers lines each provided with a meter or call register, means including a trunk line for establishing a talking circuit between a calling line and a called line, arelay in said talking circuit individual. to said trunk line for controlling the meter associated with a connected calling line, and a second rela connected in bridge of the connected called line for controlling said first relay.

2%. In a telephone system, subscribers lines each provided with a meter or call register, a trunk line, individual switches for said lines having access to said trunk line whereby a calling line may be connected thereto, means including a plurality of additional automatic switches for extending the said trunk line into connection with a called line, a circuit for operating said automatic switches and a relay individual to said trunk line included in the operating circuit of said switches for operating the meter associated with the connected calling line to register the call.

25. In a telephone system, subscribers lines each provided with. a meter or call register, a trunk line, individual switches for said lines having access to said trunk line whereby a calling line may be connected thereto, means including a plurality of additional automatic switches for extending the said trunk line into connection with a called line, a circuit for operating said automatic switches, a 'relay individual to said trunk line included in the operating circuit of said switches, and acircuit under control of said relay for operating the meter associated with the connected calling line.

26. In a telephone system, subscribers lines each provided with a meter or call register, a trunk line, individual switches for said lines having access to said trunk line whereby a calling line may be connected thereto, means including a plurality of additional automatic switches for extending the said trunk line into connection with a called line, a circuit for operating said automatic switches, a relay individual to said trunk line included in theoperating circuit of said switches for operating the meter associated with the connected calling line to register the call, and a second relay controlled over the connected called line for controlling said first relay.

27. In a telephone system, subscribers" lines each provided with a meter or call register, a trunk line, individual switches for said lines having access to said trunk line whereby a calling line may be connected thereto, means including a plurality of additional automatic switches for extending the said trunk line into connection with a called line, a relay individual to said trunk line, a circuit under control of said relay for operating the meter associated with the connected calling line, and a second relay con.- trolled over the connected called line for controlling said first relay, and means for maintaining said first relay energized independent of the second relay.

In a telephone system, subscribers lines each provided with a meter or call register, means including a plurality of serially related automatic trunking switches for connecting a calling and a called line, an oper ating circuit for each dividual to a switch intermediate in the series and included in its operating circuit for controlling the operation of the meter on the connected calling line.

29. In a telephone system, subscribers lines each provided with a meter or call register, means including a plurality of serially related trunk lines for connecting a calling and called line, a relay individual to the first trunk line of the series for controlling the operation of the meter on the connected calling line, and a second relay individual to the last trunk in the series for controlling said first relay, and means for maintaining said first relay energized independent of the second relay.

30] In a telephone system, subscribers lines each provided with a meter or call register, trunk lines and automatic progressively movable switches associated therewith less in number than the number of lines for use in connecting calling and called lines, means controlled over connected called lines for altering the current flow in connected calling lines, and relays for controlling the meters of connected calling lines in response to alterations of current flow therein, each relay being individual to a trunk line where. by a small number of.relays is enabled to control a large number of meters.

81. In a telephone system, subscribers lines each provided with a meter or call-register, means including a trunk line terminating in an automatic progressively movable switch for connecting any line when calling with a called line, a relay individual to said trunk line and responsive to current variations in the circuit of a connected calling line, and a meter control circuit completed during the establishment of a. connection whereby the meter associated with the call ing line is brought under control of said relay.

32. In a telephone system, subscribers lines each provided with a meter or call register, means including a trunk line terminating in an automatic progressively movable switch for connecting any line when calling with 2. called line, a relay individual to said 8O switch, and a relay in trunk line for controlling the motor associ- In testimony whereof I affix my signature ated witli p connected calling line and a in the presence of two witnesses. Winding of said relay including a. talking ARTHUR J. RAY. conductor of the trunk, whereby the relay is Witnesses:

rendered responsive to a current variation J.-DUCKERS,

in the calling line circuit. v H. WILLIAMS. 

